Solve for $x$ : $-28 + x = -16$
Answer: Add $28$ to both sides: $ \begin{eqnarray} \\ -28 + x &=& -16 \\ \\ {+28} && {+28} \end{eqnarray} $ $ \begin{eqnarray} \hphantom{-28 + x} &\hphantom{=}& \hphantom{-16} \\ x &=& -16 {+ 28} \\ \end{eqnarray} $ Simplify. $ x = 12$